448 LIQUID PARTS OF ANIMALS. 



lyzed it in the following manner : An egg was boiled hard in 

 distilled water, and the yolk in that state was found to weigh 

 316*5 grains. It was then partially dried by exposure to the 

 air for several weeks, and to remove the remainder of the water, 

 it was reduced to powder and dried in a heat somewhat more 

 than 212. The total loss of weight was 170*2 grains, which 

 was considered as owing to the escape of water. The residue was 

 digested repeatedly in alcohol of 0*807 till that liquid came off 

 colourless. What remained was a white powder possessing many 

 of the properties of coagulated albumen, but differing from that 

 principle by the large quantity of phosphorus which it contained 

 in some unknown state of combination. The alcoholic solution 

 was of a deep-yellow colour, and deposited crystals of a sebace- 

 ous matter, and a portion of yellow semifluid oil. On distilling 

 off the alcohol the oil was obtained in a separate state. On 

 cooling, it became nearly solid, and weighed 91 grains. The al- 

 bumen weighed 55*3 grains. Hence the yolk consisted of, 



Grains. 



Water, v 170-2 or 53-78 

 Albumen, . 55-3 or 17*47 



Yellow oil, . 91*0 or 28*75 



316-5 100*00 



But he found these proportions to vary a little in different eggs.* 

 According to Planche, 1000 parts of yolk of egg furnish at 

 an average 180 parts of oil. This oil consists of stearin and elain 

 in the following proportions : 



Stearin, . 10 

 Elain, . 90 



100 



The stearin is white, solid, and does not stain paper like oil. 

 100 parts of boiling alcohol, of the specific gravity 0*805, dis- 

 solve 10*46 parts of this stearin. He found the stearin from the 

 fat of fowls of a fine white colour, and 100 parts of alcohol of 

 0*805 dissolved 10'09 parts of it, showing it to agree very near- 

 ly with the stearin from the yolk of egg.f 



The elain from the yolk possesses the characters of a fixed oil, 

 but has not hitherto been subjected to a chemical investigation. 



* Phil. Trans. 1822, p. 387. f Jour, de Pharmacie, ix. 2. 



